Opticast is an automated forecasting system designed to produce detailed forecasts for specific times of each day. The system works by taking forecasts from a range of computer models and comparing them with past observations to produce the most accurate possible forecast possible, tailored to a specific location where weather observations are taken.

Opticast allows you to 'drill-down' into the daily forecast, giving you a more exact idea of your local conditions at particular times of interest to you. For example, if you cycle to work you are likely to be most interested in the temperature, wind and chance of rain at 6am and 9pm. Or if you're organising an afternoon party and the daily forecast is for late thunder, you'll want to know what time the bad weather is likely to arrive.